An endoscope is a flexible instrument introduced into the body to examine the inside of the body. In addition to a light source and a camera at the distal end (the end which is inside the body), typical endoscopes may also include a plurality of lumens running therethrough for different tasks. These lumens may include an illumination lumen, viewing lumen, irrigation lumen, aspiration lumen and one or more working lumens. An endoscope is introduced into the body through a body orifice (such as, the rectum or mouth) or a small incision. To minimize human discomfort and maintain flexibility of the endoscope, the diameter of an endoscope is minimized. This restriction on size of the endoscope limits the number and size of the lumens.
Endoscopic instruments, configured to perform different diagnostic and therapeutic tasks, may be delivered to a work site inside the body through the working lumen. From its early use as a purely visual diagnostic tool, endoscopes, along with endoscopic instruments, have grown rapidly to provide an impressive array of therapeutic options. The endoscope can be used for therapeutic purposes in a variety of ways. In some instances, the endoscope serves as a means of access to an appropriate internal body part, allowing the accurate placement of a drug (or other device) on that part, using an endoscopic tool configured for the task. An endoscopic instrument configured for other tasks, for example, a biopsy forceps instrument, may also be delivered to the internal body part through the working lumen. The biopsy forceps instrument may be used to obtain a tissue sample from the body part (for example, the colon). Once the tissue sample has been acquired, the biopsy forceps instrument may be retracted out of the endoscope, and the tissue sample removed from the biopsy forceps instrument.
Endoscopic tools configured for surgical functions (incision, grasping, stitching, cauterizing, etc.) may also be delivered through the working lumens of an endoscope to perform endoscopic surgical procedures. In these instances, the form of the endoscope and the associated instruments may impose physical limits on the surgical task that can be accomplished. These limitations, in some cases, may restrict endoscopic procedures from producing the same anatomical outcome as conventional surgery. Some of these limitations may include the small physical size and number of endoscopic instruments that may be delivered through the working lumen of the endoscope, and the limited maneuverability of the working ends of the endoscopes and endoscopic instruments. There may also be concerns regarding contaminating the working lumens of endoscopes which may result in infections.
Many surgical procedures may require multiple surgical instruments at the working site at the same time. As mentioned earlier, these surgical instruments are typically delivered through the working lumens of the endoscope. The limited number of working lumens in an endoscope limits the number of instruments that can be delivered to the surgical site at a time. Also, while it is often desirable to have larger instruments at the surgical site, the small size of the working lumens limit the size of the tool that can be passed through it. This limitation on physical size also restricts the force that can be applied with the surgical instrument.
A typical endoscope may possess poor maneuverability. The working ends of a typical endoscope may be restricted to movements involving pushing/pulling or limited torque. Similar constraints may apply to instruments introduced via the working lumens. Effective surgery may require that surgical tools possess the ability to, for example, cut and stitch precisely. These requirements may necessitate the precise movement of endoscopic instruments in multiple dimensions. The limited freedom of movement of the working ends of endoscopes and endoscopic tools may hinder these tasks. Ideally, the working ends of endoscopic tools may be configured to move in three dimensions and converge on a given point (a concept referred to as triangulation).